The present invention relates to a door handle apparatus, and more particularly to a door handle which is preferably used for a smart entry system equipped on an automobile.
Conventionally, there has been known an automobile which is equipped with, as an automotive security system, a so-called smart entry system in which a recognition code is exchanged between a transmitter-receiver carried by an operator (for example, the driver) and a transmitter-receiver provided on the automobile side, whereby a lock of a door of the automobile is automatically opened when the operator only approaches the door of the automobile, whereas the lock of the door is automatically closed when the operator only leaves from the door.
In this system, proximity sensors are provided on automotive door handle apparatuses D1 to D3 shown in FIGS. 8A to 8C as a trigger unit for executing a recognition process.
For example, in the door handle apparatus D1 using a handle grip H (a door handle) as shown in FIG. 8A, there is a case where an electrostatic capacity-type detection sensor K as shown in FIG. 9 is integrally installed in the handle grip H. In this door handle apparatus D1, a recognition process is designed to be executed by detecting a change in voltage that would occur when the operator P touches the surface of the handle grip H by making use of electrostatic capacity which changes when the touch of the operator P on the handle grip H occurs (for example, refer to a patent document No. 1).
In addition, in the door handle apparatus D2 using a flap F (a door handle) as shown in FIG. 8B, there is a case where an antenna A as shown in FIG. 9B is provided in the interior of a door as a detection sensor. In this door handle apparatus D2, a recognition process is executed by applying a radio wave transmitted from the antenna A to an object such as the fingers of the operator P and then detecting the amount of attenuation of the radio wave and a delay in time due to the reflection of the radio wave on the fingers.
The configurations for executing the recognition process by using the detection sensor K and the antenna A can also be adopted for the door handle apparatus D3 provided with a door handle DH and a cover member C in a back door BD as shown in FIG. 8C.
[Patent Document No. 1]
JP-A-2002-295094 (paragraphs 0015 to 0018, FIG. 2) In the door handle apparatus D1 shown in FIG. 8A, however, since the detection sensor K (refer to FIG. 9A) is constructed to be installed in the handle grip H, there is caused a problem that the size of the detection sensor K is limited, and since a construction is needed to enable the installation of the sensor, there is caused another problem that the design of the handle grip H is limited. In addition, there is caused a further problem that the apparatus D1 is inferior in versatility (application to other types of automobiles).
Incidentally, it is desirable that the smart entry system is constructed so as to allow for a selection of fitment or non-fitment of the system depending on types of vehicles. With the constructions adopted for the detection sensor K and the antenna A shown in FIGS. 9A, 9B, however, the specification needs to be changed largely depending on whether or not the detection sensor K and the antenna A are equipped. Due to this, the construction around the handle needs to be designed so as to allow for a change in specification depending on whether or not the sensor is equipped, and as a result, there is caused a problem that the related cost needs to be increased.
In addition, in the door handle apparatus D1 shown in FIG. 9A, since the detection sensor K is constructed to be integrally installed in the handle grip H, when the detection sensor K fails, there may occur a case where the replacement of parts should be dealt with by replacing the whole door handle apparatus D1, there is caused a problem that the repair cost is increased.